The expansion of Roman influence began during the period when Rome was a republic. However, political weaknesses led to power being centralized in a single figure of authority – the emperor (Latin: imperator, “one who gives orders”). For political reasons, this supreme ruler was not referred to as “king,” as this term was regarded as no longer being acceptable because of associated abuses of power in the pre-republican era. The term “emperor” was devised as a name for Rome’s supreme ruler, mainly because it avoided using language which linked it to discredited periods in Roman history. It was during the reign of the first emperor, Caesar Augustus, that the gospel of Luke places the birth of Jesus of Nazareth.
A significant degree of Roman territorial expansion took place during the reign of Augustus, especially in Egypt and northern Europe. The imperial province of Egypt became of particular importance, providing substantial grain imports to feed the Roman popula- tion. Yet Augustus’s successor Tiberius, who reigned from 14–37, proved an ineffective emperor, preferring to live in seclusion on the island of Capri. Under Trajan, however, the stability of the empire was initially restored, followed by a period of further territorial expansion. A major program of public building in Rome itself enriched the city, emphasiz- ing its status as the center of the greatest empire the world had then known.